The main purpose of this article is to explain the Kaplan turbine. So, a Kaplan turbine is a very popular type of the reaction turbine.
In a Kaplan turbine, the water enters and exits the turbine by its rotation axis (axial flow). These turbines operate at high water flow and low pressure, with maximum efficiency, which is not possible for a Francis turbine. A unique feature of the Kaplan turbine is that the leaves change, which is necessary to maintain maximum water flow efficiency. The water flowing into the turbine loses pressure.
The water that is required in order to get this kind of turbine is high and consistent with the total land area of the leaves. Because of the large area of turbines, dams with down manifolds are the most useful areas of high-water flow. This was especially important before using a Kaplan turbine. The maximum number of wind turbines, suitable only for large parts. Victor Kaplan was invented it in 1913. Victor Kaplan was the design director for this type of turbine, and the foundation was laid in the design of turbojet engines and experience in reflecting the pipe principle.
Principle of operation of the Kaplan Turbine:
The Kaplan turbine operates on the principle of an axial jet turbine. In turbines, water enters and exits the turbine’s rotation axis.
The Kaplan turbine has a low water head while has a high-water flow rate. Water enters the turbine through a guide rail to return to the ground struck. Guide sheet, so arranges enough so that the level of turbulence is determined by that of the wind turbine rotor. The water flow enters into the direction, the leaves are passed through a curved channel the flow force is parallel to the radial axis, but the first vortices that are created at the entrance of the leaves are in the form of free rotation.
Then the vortex flow makes up the forces on the knives and disappears. Therefore, both angular and linear speeds produce shaft rotation as well as torque. This is a shaft connected to a generator, the shaft rotates in the generator coil. Thus, the generation of electricity is carried out by a generator. The Kaplan turbine system for hydroelectric power is the same as the Francis turbines. So, this is the principle of operation of the Kaplan turbine.
Kaplan Turbine Components:
Kaplan turbine have blade-similar to a propeller. Secondly, the turbine axis has a leaf design, and the vanes don’t have twist shape, add a heating direction so that the water is swirled at the outlet entrance.
The blade and rotation of Kaplan’s turbines are transmitted to the generator through shaft that are long single-component, fast.
3) Guide Blade:
The guide blade is a universal component of a turbine engine. It should be turned on and off depending on the authority’s requirements. Turn the blades at a certain angle to control the flow of water.
If the power consumption is higher, let’s open it so that water can use the blade. Most likely, the power consumption is less, turn off the power to stop the flow of water. This increases the efficiency of the turbine. Without guide blades, the turbine will not be efficient, and the efficiency of the turbine will decrease.
The role of the impeller is important in the operation of the Kaplan turbine. The impeller is a rotating component of a turbine engine. It provides additional electricity generation. The water flow axis acting on the knife causes the impeller to rotate.
5) Blade control mechanism:
The blade has a soft shoulder wireless access point. A blade control mechanism that controls the angle of attack and when water occupies the blade, which causes the blade connector to rotate.
6) Scroll Casing:
The body of the Kaplan turbine is known as the hosing. View the housing to reduce the cross-sectional area. First of all, it is the water pressure flowing out of the waste spiral housing, and then the guide blades.
Water returns to 90 ° from the guide blades and flows axially through the impeller. The shell protects the back of the ground, struck, blades, steel and all other internal to the converter important components damage from the outside of the turbine.
7) Draft Tube
It is a channel that links the outlet of impeller to the tailrace and discharges the fluid from the turbine. The main function of the draft pipe is to reduce the flow rate and losses, and minimize the efficiency at the end. Drainage to reduce water velocity by increasing the water surface.
Advantages and disadvantages of Kaplan turbines:
The advantages of the Kaplan turbine are listed below.
- It has adjustable runner vanes
- It needs a shallow head.
- This turbine requires only 3 to 8 blades.
- Kaplan turbines are highly efficient.
- It requires low area for installation
The disadvantages are below:
- In these turbines, there is a cavitation problem.
- It has high price.
- The Kaplan turbine is expensive to install and design.
- These converters require a very high level of cost for mortgage payments.
- When a Kaplan turbine is running, it requires high costs, which is impossible, anywhere and anywhere.
- In heavy-duty turbines, a generator is required.